1. Field of the Invention
The present invention relates to a security cable tie comprising a strip of plastic having integrally molded at one end thereof a head. The head has a passage or opening therethrough with teeth on one side of the passage and at least one pressure rib on the other side of the passage. One side of the strip has teeth thereon which are adapted to ratchet past teeth in the passage while being biased toward the teeth by the at least one rib on the other side of the passage. Then, when a sufficient length of the strip has been pulled through the passage, the reverse movement of the strip will cause the teeth on the strip to engage and lock with the teeth on one side of the passage while the at least one rib on the other side of the passage urges the strip toward the teeth on the other side of the passage.
2. Description of the Prior Art
Heretofore a number of integral one piece cable ties have been proposed, each of them including a strip of plastic material having a head at one end thereof with a passage through the head and some form of ratcheting or pawl type structure within the passage for engaging teeth on one side of the strip of plastic material.
Examples of previously proposed cable ties are disclosed in the following U.S. patents:
All but two of the prior art U.S. patents listed above disclose some form of pawl for engaging teeth or ribs on one side of a strip of plastic.
The Davignon et al. U.S. Pat. No. 5,836,053 discloses a passage through a head at one end of a cable tie having a ramp surface on one side thereof for engaging a side of a tooth after the tooth is pulled through the passage and a cut-away groove for engaging a lower corner of an adjacent tooth, thereby to hold a plastic strip pulled through the passageway at an angle of approximately 30xc2x0 to 60xc2x0 relative to the passage.
The McInerney U.S. Pat. No. 5,911,367 discloses a passageway which extends almost parallel to the strip through a head at one end of a strip of plastic material. The head also has first and second spaced apart openings communicating with the passage whereby the other end of the strip can be pulled through the first opening through the generally axially extending passage and through the second opening and past teeth on a section of plastic in the head between the openings. A reverse pull on the strip of plastic will cause teeth on the strip to engage with teeth on the section of plastic between the openings in the head of the strip.
According to the present invention there is provided a cable tie comprising: an elongate strip and a locking head formed at one end of the strip and having a passage or opening therethrough. The strip has spaced apart teeth formed in or on one side thereof. The passage or opening in the locking head has at least one tooth on one side thereof and at least one pressure rib on the other side thereof. Further, the passage or opening in the head is constructed, sized and arranged with a distance between the one side and the other side relative to the thickness of the strip which will permit the strip to be pushed or pulled through the passage or opening with the teeth on the strip ratcheting over the at least one tooth on the one side of the passage or opening and past the at least one pressure rib on the other side of the passage or opening, and so that, when the strip is pulled or pushed in a reverse direction, the at least one rib will urge the strip and the teeth on the other side of the strip into locking engagement with the teeth on the one side of the passage or